Our group consisted of my 70-something year old parents (who treated the rest of us to this cruise), my husband & me (in our 40s), our 2 sons (ages 10 & 12) and my brother, a single 40-something. I had cruised once 20+ years ago and my parents had cruised several times but never on Princess (RCL and others).
We chose this cruise simply because it worked with everyone's schedule. Overall I highly recommend it, especially for a large group. Everyone could do their own thing. Sometimes we'd do things together but we always knew we'd meet up for dinner. The service was exceptional. We felt like we were at a 5-star hotel. From the moment we got on board, the staff was always asking us if we needed something. One night we ordered room service that never came but we forgave them because every other interaction was so wonderful.
Food: The food was much better than I expected it would be, especially the sit-down dinners. We did the early seating sit-down dinner and had our own table. Our waiter was warm, friendly and attentive. For breakfast we mostly did buffet (we did a sit-down one morning that was meh), lunches we ate burgers or the delicious fresh wood-fired pizza on deck, but every single night we did the family dinner which was a great way to end a day/begin an evening. We never tried the other restaurants because we enjoyed "our" table so much.
Rooms: My husband & I had a balcony room and our kids had an inside cabin directly across from us. (Baja deck, B419 & B421) The idea was to put 1 adult & 1 child in each room (that is how you have to book it) because we thought there would be no WAY we'd let them be in a cabin by themselves. They are barely 10 and 12 and we tend to be worriers! But after less than a day on board, we felt so comfortable and safe that we let them sleep in their room by themselves. It certainly made it more of a vacation for us! (By the way: Getting 2 rooms was only a little bit more expensive than putting the 4 of us in 1 room, and cheaper than a family suite.) My parents had a balcony room next to us with a gate that opened so we could go back and forth. My brother had a view room a couple decks away (Emerald) which he found ideal. (Tip: You can call and ask for an "obstructed view" room that does not have a lifeboat in front of it, giving you a view room for an obstructed view price.) My dad was afraid the elevators would be noisy but nobody heard a thing. The beds and pillows were super comfy and I'm picky. The only complaint was the first night, the engine was so rumbly I couldn't sleep but the rest of the trip was fine. The TVs had tons of great first-run movies (including plenty for kids) and lots of other channels including repeats of the Love Boat!
Activities: There was a schedule every day but we didn't do a ton of them. We mainly hung out around the pools & jacuzzis, reading, playing cards and chatting. The movies on deck were fun.
Excursions: In Cabo we did the Dolphin Swim which was great, though we had to wait a long time before our group was called. Had a GREAT lunch at Solomon's Landing afterwards, walking distance from the dolphin center. In Puerto Vallarta we did the zip lining which my kids are still talking about. We got pictures both places, which are expensive but worth it. (We booked both through Princess.) Ensenada was a complete waste of time: dirty, seedy, boring. Next time I wouldn't get off the boat. Speaking of getting off the boat: that was easier than I thought it would be. But I had expected to wait forever and be highly annoyed so the wait didn't seem bad!
Kids Club: My kids didn't want to go and I didn't make them. But on day 4 they met some kids on deck that had been in kid's club and from that point forward, they hung out with Kid's Club kids. If parents ok it, kids can leave the club and walk around the ship. (They could go to the sport court, play shuffleboard, get food, etc.) Amazingly, my husband and I agreed to this and the kids LOVED their independence. I can't believe we felt comfortable enough to let them do that, but the ship really felt that safe.
I could criticize some things but there was nothing that ruined the trip. For example it would have been nice to have a "funner" pool for the kids like Disney (which of course is 3x price), the entertainment wasn't memorable (except one guy in the lobby who was great), and not everything I ate was stellar. Expect some waiting around to get on/off the boat and get that first buffet meal. But overall whenever I think about that cruise I smile. Would definitely do it again. My husband did NOT want to go in the first place but is now telling everyone how great cruising is and can't wait to go back.